Tunnel kiln



3 She ts Sheet 1 TUNNEL KI June W, BOOTH NOV- I mmm G. W. BOOTH TUNNEL KILN Filed June 1 1922 3 Sheets-Sheet B INVENT'U w q MM AM 3 Nov. 13 1923.

Nov. l3 1923. 11,474,4163

G. W. BOOTH TUNNEL KILN Filed June 16. 1922 3 Sheets-Sheet 3 Patented Nov. l3, i923.

. l l i) GEORGE W. BOOTH, F ISLINGTON, ONTARIO, CANADA;

TUNNEL KIL'N.

Application filed .Tune 16, 1922.

To all whom may concern.

Be it known that I, GEORGE VV. Boo'rn, of Islington, in the county of York. Province of Ontario, Canada, a subject of the King E of Great Britain, have invented certain new and useful Improvements in Tunnel Kilns, of which the following is a specification.

This invention relates to kilns of the type disclosed in my prior United. States Patent W No. 1,403,734, dated Jan. 17th, 1922, and my object is to modify the construction of the kiln shown therein to better adapt it for use in a double tunnel construction, and to conditions in which itis desirable that the -preheating zone of the kiln shall lie alongside of the remainder of the kiln instead of in alinement therewith.

I attain my object by means of the constructions hereinafter described and illustrated in the accompanying drawings in Which-- v Fig. 1 is a plan view, partly broken away, and partly in section, of' my improved kiln; r

2 a cross section on the line 11-11 in Fig 1;

Fig. 3 a cross section on the line Ill-III in Fig. 1; v

Fig. 4 a cross section on the line IV-IV in F ig. 1; and

Fig. 5 a cross section on the line V V.

In the drawings like numerals of reference indicate corresponding parts in the different figures.

The kiln is shown as formed with two tunnels 1, which are side by side and sep arated merely by a central wall. This tun nel comprises three zones, the preheating zone extending substantially from A to B, the firing zone extends from C to D, and the cooling zone. which extends from. D to E. The pie-heating part of the kiln is shown as set to one'side, but it may, of course, as is common in the art. be extended in alinement with the other parts of the kiln.

. In the walls of the cooling zone and firing zone of the kiln is formed an air space 2, preferably extending from end to end thereof at the top of the kiln so that the air passing therethrough takes u heatfrom the upper parts of the kiln. similar air interior of the tunnel and Serial No. 568,847.

space 3 extends along the pie-heating zone of the kiln and is connected by the transverse flue at with the air space 2. In the walls of the cooling zone of the kiln are also formed air spaces 5, preferably extending from end to end thereof, and connected at intervals with the air space 2 by air passages 6 controlled by dampers 7. From openings 8-8 at the exit end of the kiln outside air is admitted to the air spaces 2 and 5. These openings are preferably damper controlled. Along the outer side of each half of the firing zone'of the kiln are located one or more furnaces 9 of any ordinary type, which communicate with the interior of the tunnel.

A bafile walllO extends up nearly to the roof of the tunnel. andis preferably formed of checker workin a well known manner, This wall serves to distribute the products of combustion in a satisfactory manner from top to bottom of the tunnel. Each part of the kiln opposite the furnace is provided with a wall 11 forming a flue 12 communicating with the interior of the tunnel 'at its lower side.

A baffle wall 13 may be provided inside this flue 12 to cause the hot products of combustion to travel up against the inner side of the wall 11, so as to maintain it in a sufficiently heated condition to radiate heat into the interior of the tunnel, thus assisting in maintaining equality of temperature at all parts of the interior of the firing zone of the kiln. The flue 12 at the inlet end of the firing zone of the kiln is connected by means of an underground transverse fine 14 with flues 15 extending longitudinally of the pre-heating zone of the kiln at the inner side of each half thereof. The walls of these fines are preferably of metal to facilitate heat exchange with the interior of the kiln at the pre-heating zone. The flues 15 are connected by a transverse flue 16 with the stack 17. Below the flues 1.5 are located the moist air fiues 18, which are provided at intervals with openings 19, preferably damper controlled, communicating with the also with the flue 16.

The air space 3, which extends along the top of the pre-heating zone of the kiln is connected at intervals by means of passages 20 with the interior of a flue 21, extending along the side of the pie-heating zone of the kiln opposite the lines 15, this flue communicating at intervals with the interior of the tunnel through openings 22. The passages '20 are preferably provided with dainpers 23, as shown, so that the How of air from the air space 3 may be regulated to suit conditions at different "parts of the preheating zone.

While the constructions hereinbefore described are particularly adapted for use in double tunnel kilns, such, as shown, it is evident that they are equally applicable in a single tunnel kiln, vof which the double tunnel kiln is merely a duplication.

I The mode of operation is substantially as follows :Air is pro-heated in the air spaces 2 and 5, and is led to the air space 3 of the p e-heating zone of the kiln, serving to heat the same by conduction through the walls, and also by direct contact with the goods in the tunnel. The hot gases from the furnace do 'not pass longitudinally through the tunnel of the firing zone, but transversely, and are led through the tines 12 to the fines 15, serving to assist in the heating of the tunnels of the pre-heating zoneof the kiln.

Moist air is led away through the fines 18 and flue 16 to the stack, and the rapidity of this air movement is controlled by the extent to which air is admitted through the passages 20 to the flue 21and thence to the interior of the tunnel. j

With the arrangements described all the advantages attained the constructions of my United States Patent No. 1,403,734 are attained, the specific construction, however, being better adapted to double tunnel kilns, and particularly where the preheating zone of the kiln located along-side instead of in alinement with the remainder of the kiln.

Suitable inlet and exit doors will, of course, be provided as is common in the art.

\Vhat I claim as my invention is 1. A tunnel kiln having an air space extending longitudinally of. the pre-heat-ing, firing and cooling zones of the kiln; a furnace at one side of the kiln communicating with the interior of the firing zone; a longitudinal flue at the opposite side of the kiln communicating with the interior of thekiln substantially opposite the furnace and extending along the pie-heating zone; a stack adjacent the inlet end of the kiln with which said flue communicates; and means forming a communication between the stack and the air space aforesaid adjacent the inlet end of the tunnel. v

"2; A tunnel kiln constructed substantially as set forth iii claim l p rovided with a moist air flue communicating with the stacker;-

tending longitudinally of the pre -heating f e'e th ln a aphas a 01 Pa s at different points longitudinally of the pre- 7 heating zone of the kiln.

3. A tunnel kiln constructed substantially as set forth in claim 1 provided with a moist air-flue con'nnnnicating with the stack extending longitudinally (a? the pie-heating zone of the kiln and a plurality of passages from the pie-heating zone to the said fine at different points longitudinally of the preheating zone of the kiln, and a series of damper controlled openings between the air space and the interior of the tunnel at different points longitudinally of the pre-heating zone of the kiln.

l. A tunnel kiln constructed substantially as set forth in claim lrprovided with a moist air flue at one side of the pre-heating zone and below the longitudinal flue carrying the products of combustion and a plurality of damper controlled passages betweenithe air space and the interior of the tunnel at different points longitudinally of the pie-heating zone of the kiln at the side opposite the moist air flue. V V

5. A tunnel kiln having a furnace at one side of the firing zone communicating with the interior; a flue at the opposite side of the firing zone of the kiln communicating with the interior of the kiln opposite the furnace;

and a stack with which said flue communii cates and a baffle wall at the furnace side of the kiln adapted to distributethe products of combustionfrom the furnace.

6. A tunnel kiln having a furnace at one side of the firing zone communicating 3 with the interior; a flue at the opposite side of the firing zone of the kiln communicating with the interior of the kiln opposite the furnace; a stack with which said flue comnunicates; a bafile wall at the furnace side of the kiln adapted to distribute the products of combustion from the furnace; and a baffle wall in the flue adapted to direct products of combustion to the top of the flue, the communicationwith the kiln being adjacent the lower part of the kiln chamber.

7. A tunnel kiln having an air space extending longitudinally of the firing andfp're heating zones of the kiln; a furnace at one side of the kiln communicating with the interior of the firing zone; a longitudinal flue at the opposite side of the kiln communicat ing with the interior of the kiln substantially opposite the furnace and extending along the pie-heating zone; a stack adjacent the inlet end of the kiln with which said flue communicates; and means forming a com munication between the stack and the air space aforesaid adjacent the inlet end of the tunnel. 7

8. A tunnel kiln having an airspace extending, longitudinally of the cooling and preheating zones "of the kiln; a furnaceat one side of the kiln communicating with the interior of the firing zone; a longitudinal flue at the opposite side of the kiln communicating with the interior of the kiln substantially opposite the furnace and extending along the pre-heating zone; a stack adjacent the inlet end of the kiln with which said flue communicates; and means forming of the tunnel.

Signed at T0ronto,-Can., this 9th day of June, 1922.

GEORGE W. BOOTH. 

